In at least some of the past gas turbine engines, a plurality of nut and bolt assemblies formed a generally circular bolted joint between casings of the gas turbine engine (e.g., the bolted joint between a turbine forward stator casing and a turbine aft stator casing), and the casings defined a chamber which is exposed to a gasflow (e.g., airflow and/or combustion gasses) therein when the engine is operating. Whenever the bolt heads or nuts of the aforementioned nut and bolt assemblies extended into the chamber so as to be exposed to the airflow (for example) therein, it was believed to be prudent to shield such bolt heads or nuts in order to minimize air temperature rise due to windage. This shielding was believed to be necessary especially when the airflow in the chamber was utilized as a cooling medium for other downstream components of the gas turbine engine.
At least some of the past shields for the aforementioned bolt heads or nuts at the bolted joint comprised a fully machined ring, a formed sheet metal ring, or sheet metal segments assembled into a ring, and such past shields were retained in overlaying relation with such bolt heads or nuts in the chamber by utilizing some portions of the bolts at the bolted joint. Of course, such mounting of the past shields to the bolts at the bolted joint required a plurality of cutouts or openings in such past shields in order to provide access for torquing the bolt heads or nuts. One disadvantageous or undesirable feature of the past shields is believed to be that the aforementioned cutouts therein may have created disturbances in the air flow in the chamber thereby to contribute to undesirable windage and temperature rise in such air flow. Further, another disadvantageous or undesirable feature of the past shields is believed to be that the cutouts therein may have allowed the circulation of air and abrasive dust particles within such past shields which might have caused erosion problems. Of course, when the past shields were fully machined rings, the aforementioned erosion concern may have been eliminated, but such fully machined rings are believed to be too heavy for use in the gas turbine engine and still required cutouts for access to torque the nuts or bolts at the bolted joint.